I was told that there wasn't a Dana narrow enough to go under the rear of a '69 A-Body and the 4-speed 440 (B-Bodies also) required the Dana rear.
Yes, that is why they used a B=Body rear on the 68 Hemi A-Body's. The guy who started the GTS registry had a 69 383 4-speed GTS convertible that had A/C. He bought it new and had the dealer order every part out of the parts book for a 340 Dart and B-Body engine components and had it all installed at the dealership, everything worked perfectly, there was no reason they couldn't have offered it as an option. The only reason that anyone can figure out was they were worried about overheating...
The funny thing about science is that if you change one miniscule parameter you change the entire outcome to the way you want it.
